Details

Autor(en) / Beteiligte

• Still, Tim
• Yunker, Peter J
• Yodh, Arjun G

Titel

Surfactant-Induced Marangoni Eddies Alter the Coffee-Rings of Evaporating Colloidal Drops

Ist Teil von

• Langmuir, 2012-03, Vol.28 (11), p.4984-4988

Ort / Verlag

Washington, DC: American Chemical Society

Erscheinungsjahr

2012

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The influence of the small ionic surfactant sodium dodecyl sulfate (SDS) on the evaporation of drying colloidal droplets is quantitatively investigated. The addition of SDS leads to a significantly more uniform deposition of colloidal particles after evaporation (i.e., the so-called “coffee-ring effect” is dramatically altered). We understand this phenomenon in the context of circulating radial Marangoni flows induced by the variation of SDS concentration along the air–water interface. Video microscopy permits the direct visualization of the colloidal particles involved in these flows, revealing a surprisingly stable “Marangoni eddy” that prevents particle deposition at the drop perimeter.